Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro...
Transcript of Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro...
![Page 1: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/1.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc.
FTF-ENT-F0174
Solutions for EMC Issues in Automotive System Transmission Lines
June 23, 2010
Todd HubingClemson University
![Page 2: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/2.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 2
► In automotive systems, the wiring harnesses play a key role in couplingelectronic noise to and from the components. Shielding and filtering of the wiringharness and connector are not generally viable options; therefore it is importantto address cable coupling issues with proper board-level design practices. Thispresentation reviews the various cable-coupling mechanisms and groundingstrategies. It also discusses the options available at the board level for ensuringthat automotive components do not put excessive amounts of noise on theharness and that noise on the harness does not affect the proper operation ofthe component circuitry.
► This session is intended to help the attendees learn to design electroniccomponents that function properly in harsh electromagnetic environments.
► Todd Hubing is the Michelin Professor of Vehicle Electronics at the ClemsonUniversity International Center for Automotive Research. He has over 25 yearsexperience designing products that meet electromagnetic compatibilityrequirements.
► This session is divided into four 40-minute presentations with 10 minutesallocated for questions and one 10-minute break each hour.
Session Introduction
![Page 3: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/3.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 3
►After completing this session you will be able to: • Anticipate possible Electro Magnetic Compatibility
(EMC) problems with your product designs• Make design decisions affecting the cost and
performance of your products• Specify grounding and shielding requirements for your
products
Session Objectives
![Page 4: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/4.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4
Agenda
1. When is a wiring harness a transmission line, and when is it just a bundle of wires?
2. If it’s just a bundle of wires, why do I care how it’s configured or routed?
3. When do wiring harnesses look like antennas?
4. How do I design automotive components to prevent harnesses from radiating?
5. How do I protect automotive components from noise or transients on the wiring harness?
4
14:00
15:00
16:00
17:00
18:00
![Page 5: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/5.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5
When is a wiring harness a transmission line?
5
![Page 6: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/6.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6
When is a wiring harness a transmission line?
6
► Characteristic impedance: Z0, the ratio of voltage to current in a forward traveling wave.
► For a pair of wires side-by-side:
► For a pair of wires in the same bundle: Z0 is 100 to 300 ohms.
μ 10
dZ cosh ohms2aε
−=wire spacing
wire radius
![Page 7: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/7.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7
When is a wiring harness a transmission line?
7
► Steady state solution is always the wire-pair solution
► If we don’t care about how we get to the steady state, then we don’t need to worry about transmission line solutions.
► In most automotive applications, we don’t care!
![Page 8: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/8.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 88
Signal Termination
Eliminating ringing with a series resistor
Matched terminations
![Page 9: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/9.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9
If it’s just a bundle of wires, why do I care how it’s configured or routed?
9
![Page 10: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/10.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 10
Common Impedance Coupling
10
![Page 11: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/11.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 11
Where does the return current flow?
11
![Page 12: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/12.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 12
Where does the return current flow?
12
![Page 13: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/13.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 13
Identify Current Paths
13
Current takes the path of least impedance!
> 100 kHz - This is generally the path of least inductance
< 10 kHz - This is generally the path(s) of least resistance
![Page 14: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/14.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 14
Identify Current Paths
14
![Page 15: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/15.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 15
Identify Current Paths
15
![Page 16: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/16.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 1616
Identify Current Paths
Where does the 10 kHz return current flow?
![Page 17: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/17.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 17
Conducted Coupling
17
VS1VS2
RS1 RS2
RL1RL2RRET
I
I2
1
IRET VRL2 VRL1
+ +
--
Requires 2 conductor connections between the source and victim.
The only mechanism that couples DC level shifts.
Most likely to be dominant at low frequencies, when source and victim share a current return path.
Most likely to be dominant when sources are low impedance (high current) circuits.
aka: Common Impedance Coupling
aka – “also known as”
![Page 18: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/18.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 18
Conducted Coupling Examples
18
Lights dim and radio dies when automobile engine is started.
Power bus voltage spikes are heard as audible “clicks” on an AM radio using the same power source.
An electrostatic discharge transient resets a microprocessor causing a system to shutdown.
A lightning-induced transient destroys the electronic components in a computer with a wired connection to the internet.
![Page 19: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/19.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 19
Electric Field Coupling
19
S 2 L2RL2
RL1S 2 L2
12
R || RVCrosstalk 20 log 20 logV 1R || R j Cω
= =⎛ ⎞+ ⎜ ⎟⎝ ⎠
![Page 20: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/20.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 20
Electric Field Coupling
20
Requires 0 conductor connections between the source and victim.
Coupling proportional to dV/dt.
Most likely to be dominant at higher frequencies.
Most likely to be dominant when sources are high impedance (high voltage) circuits.
aka: Capacitive Coupling
![Page 21: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/21.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 21
Electric Field Coupling Examples
21
Coupling from circuit board heatsinks to cables or enclosures.
AM radio interference from overhead power lines.
Automotive component noise picked up by the rod antenna in CISPR 25 “radiated” emissions tests.
Microprocessor resets due to indirect electrostatic discharges.
![Page 22: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/22.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 22
Magnetic Field Coupling
22
S2
RL2 12 L2
RL1 L1 L2 S2 22when V 0
V M RCrosstalk =20 log 20 logV R R R j L
ωω
=
⎛ ⎞= ⎜ ⎟+ +⎝ ⎠
![Page 23: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/23.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 23
Magnetic Field Coupling
23
Requires 0 conductor connections between the source and victim.
Coupling proportional to dI/dt.
Most likely to be dominant at higher frequencies.
Most likely to be dominant when sources are low impedance (high current) circuits.
aka: Inductive Coupling
![Page 24: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/24.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 24
Magnetic Field Coupling Examples
24
Coupling from power transformers or fluorescent lighting ballasts.
Jitter in CRT displays.
60 Hz “hum” in a handheld AM radio.
Hard-drive corruption due to motor or transformer currents.
![Page 25: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/25.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 25
When do wiring harnesses look like antennas?
25
![Page 26: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/26.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 2626
Identifying Antennas
λ/2
λ/4 Quarter-Wave Monopole
Half-Wave Dipole
• Size
• Two Halves
Electrically Small Loop
What makes an efficient antenna?
![Page 27: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/27.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 2727
Good Antenna Parts Poor Antenna Parts
<100 MHz >100 MHz <100 MHz >100 MHz
•Cables •Heatsinks
•Power planes
•Tall components
•Seams in shielding enclosures
•Microstripor striplinetraces
•Anything that is not big
•Microstripor striplinetraces
Free-space wavelength at 100 MHz is 3 meters
Identifying Antennas
![Page 28: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/28.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 2828
Common-Mode vs. Differential Mode
rzfI
1026.1E c6max
Δ×= −
rzsfI
1032.1E2
d14max
Δ×= −
⎟⎠⎞
⎜⎝⎛Δ
×= −
λs
rzfI
104 d6
zΔ
s
Identifying Antennas
![Page 29: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/29.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 2929
Voltage-Driven Mechanism
How are common-mode currents induced on cables?
~
CableEquivalent voltage
VCM
sinheat kCM DM
board
CV VC
= maxsin
0.2234 boardDM
heat k board cable
C rV EC F F
= × ×
~VDM Noise voltage
Heatsink
![Page 30: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/30.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 3030
How are common-mode currents induced on cables?
Signal current loop induces a voltage between two good antenna parts.
- Vcm +
At 10 MHz and higher, milliamps of current flowing in a ground plane produces millivolts of voltage across the
ground plane. A few millivolts driving a resonant antenna can result in radiated fields exceeding FCC limits.
Current-Driven Mechanism
![Page 31: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/31.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 3131
How are common-mode currents induced on cables?
Signals coupled to I/O lines can carry high frequency (HF) power off the board.
Direct-Coupling Mechanism
![Page 32: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/32.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 3232
How are common-mode currents induced on cables?
DM-to-CM conversion due to cable and load imbalance
![Page 33: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/33.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 33
How do I design components to prevent harnesses from radiating?
33
► Don’t rely on EMC Design Guidelines
► Be familiar with currents and current paths
► Learn to recognize good electromagnetic interference (EMI) sources
► Learn to recognize good antennas
► Be aware of fundamental EMI radiation mechanisms
![Page 34: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/34.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 34
Don’t Rely on EMC Design Guidelines
34
Board Level – Trace routing
► No trace unrelated to I/O should be located between an I/O connector and the device(s) sending and receiving signals using that connector.
► All power planes and traces should be routed on the same layer.► A trace with a propagation delay more than half the transition time of the signal it carries must have a matched
termination.► Capacitively-loaded nets must have a total source impedance equal to or greater than one-quarter of the line
characteristic impedance or a series resistor must be added to meet this condition.► Nets driven at faster than 1V/ns slew rate must have a discrete series resistor at the source.► Guard traces should be used to isolate high-speed nets from I/O nets.► Guard traces should be connected to the ground plane with vias located less than one-quarter wavelength apart at the
highest frequency of interest.► All power and ground traces must be at least three times the nominal signal line width. This does not include guard
traces.► If a ground or power separation is required, the gap must be at least 3 mm wide.► Additional decoupling capacitors should be placed on both sides of a power or ground plane gap.► Critical nets should be routed in a daisy chain fashion with no stubs or branches.► Critical nets should be routed at least 2X from the board edge, where X is the distance between the trace and its return
current path.► Signals with high-frequency content should not be routed beneath components used for board I/O.► Differential pairs radiate much less than single-ended signals even when the traces in the pair are separated by many
times their distance above a ground plane. However, imbalance in the pair can result in radiation comparable to an equivalent single-ended signal.
► The length of high-frequency nets should be minimized.► The number of vias in high-frequency nets should be minimized.► On a board with power and ground planes, no traces should be used to connect to power or ground. Connections should
be made using a via adjacent to the power or ground pad of the component.► Gaps or slots in the ground plane should be avoided. They should ONLY be used in situations where it is necessary to
control the flow of low-frequency (i.e. less than 100 kHz) currents.
![Page 35: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/35.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 35
EE371 Design Problem
35
![Page 36: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/36.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 3636
EMC Design Guideline Collection
http://www.cvel.clemson.edu/emc/tutorials/guidelines.html
![Page 37: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/37.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 37
Identify Current Paths
Where does the 56 MHz return current flow?
37
![Page 38: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/38.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 3838
Control Transition Times
t
t
f
Control transition times of digital signals!
f
![Page 39: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/39.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 3939
Control Transition Times
CMOS Driver Model CMOS Input Model
![Page 40: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/40.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4040
Control Transition Times
Digital Signal Currents in CMOS Circuits
t
t
f
f
Control transition times of digital signals:
Can use a series resistor or ferrite when load is capacitive.
Use appropriate logic for fast signals with matched loads.
![Page 41: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/41.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4141
Control Transition Times
Reducing risetime with a series resistor
Reducing risetime with a parallel capacitor
Good idea Bad idea
![Page 42: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/42.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 42
Noise Sources and Coupling Mechanisms
42
![Page 43: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/43.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4343
Clocks
Digital Data
Analog signals
Power supply switching
Arcing
Parasitic oscillations
Identify Sources
Narrow band, consistent
Not as narrow as clocks, but clock frequency is usually identifiable.
Bandwidth determined by signal source, consistent
Appears broadband, but harmonics of switching frequency can be identified, consistent
Broadband, intermittent
Narrowband, possibly intermittent
![Page 44: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/44.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4444
Active Devices (Power Pins)
Identify Sources
For some ICs, the high-frequency currents drawn from the power pins can be much greater than the high-frequency currents in the signals!
![Page 45: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/45.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4545
Noise on the low-speed I/O
For some ICs, significant high-frequency currents appear on low-speed I/O including outputs that never change state during normal operation!
Identify Sources
![Page 46: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/46.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 46
Circuit Board Grounding, Filtering and Shielding
46
![Page 47: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/47.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4747
Ground vs. Signal Return
“Whenever I see more than one ofthese symbols on the schematic, Iknow there is [EMC] work for ushere.”
T. Van Doren
AGND
DGND
![Page 48: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/48.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4848
The purpose of a system ground is to provide areference voltage and/or a safe path for fault currents.
Ground vs. Signal Return
Signal currents flowing on a “ground” conductor canprevent a ground conductor from serving its intendedpurpose.
Don’t confuse ground conductors with signal returnconductors. Rules for the routing of “ground” may conflictwith the rules for routing signal or power returns.
![Page 49: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/49.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 4949
Ground vs. Signal Return
Circuit boards should have high-frequency ground!
Conductors referenced to different grounds can be good antennas.
Signals referenced to two different grounds will be noisy (i.e., include the noise voltage between the two grounds.)
Layouts with more than one ground are more difficult, require more space, and present more opportunities for critical mistakes.
Excuses for employing more than one ground are generally based on inaccurate or out-dated information.
Why?
![Page 50: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/50.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5050
Ground vs. Signal Return
If grounds are divided, it is generally to control the flow of low-frequency (<100 kHz) currents.
For example,
Isolating battery negative (i.e. chassis ground) from digital ground
Isolating digital ground from analog ground in audio circuits.
This can be necessary at times to prevent common impedancecoupling between circuits with low-frequency high-current signals andother sensitive electronic circuits.
HOWEVER, it is still necessary to ensure that there is only 1 high-frequency ground.
![Page 51: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/51.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5151
Ground vs. Signal Return
D/A
Exercise: Trace the path of the digital and analog return currents.
![Page 52: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/52.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5252
Ground vs. Signal Return
D/A
Exercise: Trace the path of the digital and analog return currents.
![Page 53: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/53.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5353
Ground vs. Signal Return
D/A
Exercise: Trace the path of the digital and analog return currents.
![Page 54: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/54.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5454
Ground vs. Signal Return
Design Exercise: What is wrong with this design and how would you improve it?
![Page 55: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/55.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 55
Lateral Isolation
55
Digital GND
Analog GND
Chassis GND
Rarely appropriate
Often the source of significant problems
![Page 56: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/56.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 56
Vertical Isolation
56
Digital GND
Analog GND
Chassis GND
Only one plane usually needs to be full size.
One or zero vias should connect planes with different labels.
![Page 57: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/57.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5757
Ground vs. Signal Return
You don’t need to gap a plane to control the flow of high frequency(> 1 MHz) currents. If you provide a low-inductance path for thesecurrents to take, they will confine themselves to this path very well.
![Page 58: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/58.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5858
Ground vs. Signal Return
Rules for gapping a ground plane:
1. Don’t do it!
2. If you must do it, never ever allow a trace or another plane to cross over the gap.
3. If you must do it, never ever place a gap between two connectors.
4. Remember that the conductors on either side of the gap are at different potentials.
5. See Rule #1!
![Page 59: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/59.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 5959
![Page 60: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/60.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 60
Sensitive A/D Isolation
60
Digital GND
Analog GND
ONE VIA
Digital GND
If you think you need two vias, then you shouldn’t be isolating the analog and digital grounds.
![Page 61: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/61.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6161
Exceptions:
When there is no chassis ground
When there are no connectors with cables
Cables and enclosures are both good antenna parts. If they are not held to the same potential, they are likely to create a radiation problem.
Note: Sometimes low-frequency isolation between chassis and digital ground isnecessary control the flow of low-frequency currents. However, even in thesesituations it is usually important to provide a good high-frequency connection.
Provide a Good HF Chassis Ground at the Connector
![Page 62: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/62.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 62
Isolating Chassis and Digital Grounds
62
![Page 63: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/63.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 63
Caps with traces
Better implementation
63
![Page 64: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/64.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6464
Low-Pass Filters
Filtering
![Page 65: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/65.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6565
Filtering
Design Exercise: Which low-pass filter is most appropriate in each case?
![Page 66: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/66.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6666
Filtering
Parasitics
![Page 67: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/67.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6767
Two capacitors more than twice as good as one.
Filtering with Two Capacitors
![Page 68: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/68.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6868
Shielding
Electric Field
Shielding
![Page 69: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/69.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 6969
Shielding
Magnetic Field
Shielding
(at low frequencies)
![Page 70: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/70.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7070
Shielding
Magnetic Field
Shielding
(at high frequencies)
![Page 71: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/71.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7171
Shielding
Enclosure
Shielding
![Page 72: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/72.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 72
DC Power Distribution and Decoupling
72
![Page 73: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/73.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7373
Printed Circuit Board
Power Supply
VVsupplyboard
LG
LP
The Concept of Power Bus Decoupling
![Page 74: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/74.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7474
The Concept of Power Bus Decoupling
Printed Circuit Board
Power Supply
VVsupplyboard
L G
LP
Vinductance
Vinductance
![Page 75: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/75.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7575
C b
traceL
traceL
traceLtraceL
Cd Cd
L d L d
The Concept of Power Bus Decoupling
![Page 76: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/76.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 76
Effective Strategies for Choosing and Locating Printed Circuit Board Decoupling Capacitors
76
![Page 77: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/77.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7777
Rules for PCB Decoupling?
Use small-valued capacitors for high-frequency decoupling.
Use capacitors with a low ESR!
Avoid capacitors with a low ESR!
Use the largest valued capacitors you can find in a given package size.
Locate capacitors near the power pins of active
devices.
Locate capacitors near the ground pins of active
devices.
Location of decoupling capacitors is not relevant.
Run traces from device to capacitor, then to power planes.
Never put traces on decoupling capacitors.
Use 0.01 μF for local decoupling!
Use 0.001 μF for local decoupling!
Local decoupling capacitors should have a range of values from 100 pF to 1 μF!
![Page 78: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/78.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7878
How much capacitance do you need?
sourceLf
ZfC
ZCf
20
max0min
max0
)2(1
21
21
π
π
π
=
=
=
)()(
)(max fIfV
fZMAXDEVICE
MAXNOISE=
Impedance approach
maxZ
0f 1f
tracefLπ2Cf121π
Cb
traceL traceL
traceLtraceL
![Page 79: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/79.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 7979
How much capacitance do you need?
Recognizing that CMOS loads are capacitances, we are simplyusing decoupling capacitors to charge load capacitances.
Total decoupling capacitance is set to a value that is equal to the total device capacitance times the power bus voltage divided by the maximum power bus noise.
Capacitance Ratio Approach
![Page 80: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/80.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8080
How much capacitance do you need?
Let’s do it the way that worked forsomebody at sometime in the past.
“… include one 0.01 uF local decoupling capacitor for each VCC pin of every active component on the board plus 1 bulk decoupling capacitor with a value equal to 5 times the sum of the local decoupling capacitance.” .
Guidelines approach
![Page 81: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/81.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8181
Printed Circuit Board Decoupling Strategies
![Page 82: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/82.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8282
Boards with Closely Spaced Power Planes
Power Distribution Model ~ (5 - 500 MHz)
Cb
Cd
Board with power and ground planes
Cd
![Page 83: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/83.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8383
Boards with Closely Spaced Power Planes
C = 1 μFBULK C = 10nFD
L = 5 nHBULK L = 2nHDC = 3.4 nFB
0.1
1.
10.
100.
1 MHz 100 MHz0.1 MHz 1 GHz10 MHz
Bare Board
Board withdecoupling
![Page 84: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/84.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8484
For Boards with “Closely-Spaced” Planes
► The location of the decoupling capacitors is not critical.
► The value of the local decoupling capacitors is not critical, but it must be greater than the interplane capacitance.
► The inductance of the connection is the most important parameter of a local decoupling capacitor.
► None of the local decoupling capacitors are effective above a couple hundred megahertz.
► None of the local decoupling capacitors are supplying significant charge in the first few nanoseconds of a transition.
![Page 85: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/85.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8585
![Page 86: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/86.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8686
Inductance of Connections to Planes
On boards with closely spaced power and ground planes:
Generally speaking, 100 decoupling capacitors connected through 1 nH of inductance will be as effective as 500 decoupling capacitors connected through 5 nH of inductance.
5 nH 0.5 nH
![Page 87: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/87.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 87
Power Bus Decoupling Strategy
87
With closely spaced (<.25 mm) planes
► Size bulk decoupling to meet board requirements► Size local decoupling to meet board requirements► Mount local decoupling in most convenient locations► Don’t put traces on capacitor pads► Too much capacitance is ok► Too much inductance is not ok
References:
T. H. Hubing, J. L. Drewniak, T. P. Van Doren, and D. Hockanson, “Power Bus Decoupling on Multilayer Printed CircuitBoards,” IEEE Transactions on Electromagnetic Compatibility, vol. EMC-37, no. 2, May 1995, pp. 155-166.
T. Zeeff and T. Hubing, “Reducing power bus impedance at resonance with lossy components,” IEEE Transactions onAdvanced Packaging, vol. 25, no. 2, May 2002, pp. 307-310.
M. Xu, T. Hubing, J. Chen, T. Van Doren, J. Drewniak and R. DuBroff, “Power bus decoupling with embedded capacitance inprinted circuit board design,” IEEE Transactions on Electromagnetic Compatibility, vol. 45, no. 1, Feb. 2003, pp. 22-30.
![Page 88: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/88.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8888
Boards with Power Planes Spaced >0.5 mm
Cb
CdCd
![Page 89: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/89.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 8989
Boards with Power Planes Spaced >0.5 mm
On boards with a spacing between power and ground planes of ~30 mils (0.75 mm) ormore, the inductance of the planes can no longer be neglected. In particular, the mutualinductance between the vias of the active device and the vias of the decouplingcapacitor is important. The mutual inductance will tend to cause the majority of thecurrent to be drawn from the nearest decoupling capacitor and not from the planes.
ACTIVE DEVICE
LOOP A LOOP A and LOOP B
DECOUPLINGCAPACITOR
SIGNAL PLANEPOWER PLANE
GROUND PLANESIGNAL PLANE
PORT 1 PORT 2
LTRACE
LTRACE
CBOARD
VIAL
VIAL
M
![Page 90: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/90.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9090
Where do I mount the capacitor?
VCC
GND Here?
Here?
POWER
GND
![Page 91: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/91.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9191
![Page 92: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/92.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9292
For Boards with “Widely-Spaced” Planes
► Local decoupling capacitors should be located as close to the active device as possible (near pin attached to most distant plane).
► The value of the local decoupling capacitors should be 10,000 pF or greater.
► The inductance of the connection is the most important parameter of a local decoupling capacitor.
► Local decoupling capacitors can be effective up to 1 GHz or higher if they are connected properly.
![Page 93: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/93.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9393
![Page 94: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/94.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9494
Power Bus Decoupling Strategy
With Widely Spaced (>.5 mm) Planes:
► Size bulk decoupling to meet board requirements► Size local decoupling to meet device requirements► Mount local decoupling near pin connected to furthest plane► Don’t put traces on capacitor pads► Too much capacitance is ok► Too much inductance is not ok
References:
J. Chen, M. Xu, T. Hubing, J. Drewniak, T. Van Doren, and R. DuBroff, “Experimental evaluation of power bus decoupling on a 4-layerprinted circuit board,” Proc. of the 2000 IEEE International Symposium on Electromagnetic Compatibility, Washington D.C., August2000, pp. 335-338.
T. H. Hubing, T. P. Van Doren, F. Sha, J. L. Drewniak, and M. Wilhelm, “An Experimental Investigation of 4-Layer Printed Circuit BoardDecoupling,” Proceedings of the 1995 IEEE International Symposium on Electromagnetic Compatibility, Atlanta, GA, August 1995, pp.308-312.
J. Fan, J. Drewniak, J. Knighten, N. Smith, A. Orlandi, T. Van Doren, T. Hubing and R. DuBroff, “Quantifying SMT Decoupling CapacitorPlacement in DC Power-Bus Design for Multilayer PCBs,” IEEE Transactions on Electromagnetic Compatibility, vol. EMC-43, no. 4,Nov. 2001, pp. 588-599.
![Page 95: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/95.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9595
Power Bus Decoupling Strategy
With No Power Plane:
► Layout low-inductance power distribution► Size bulk decoupling to meet board requirements► Size local decoupling to meet device requirements► Two caps can be much better than one► Avoid resonances by minimizing inductance
References:
T. Hubing, “Printed Circuit Board Power Bus Decoupling,” LG Journal of Production Engineering, vol. 3, no. 12, December2000, pp. 17-20. (Korean language publication) .
T. Zeeff, T. Hubing, T. Van Doren and D. Pommerenke, “Analysis of simple two-capacitor low-pass filters,” IEEETransactions on Electromagnetic Compatibility, vol. 45, no. 4, Nov. 2003, pp. 595-601.
![Page 96: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/96.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9696
Power Bus Decoupling Strategy
Low-impedance Planes or Traces?
► Choice is based on bandwidth and board complexity► Planes are not always the best choice► It is possible to achieve good decoupling either way► Trace inductance may limit current to active devices
Planes Widely Spaced or Closely Spaced?
► Want local or global decoupling?► Want stripline traces?► Lower impedances are obtainable with closely spaced planes.
![Page 97: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/97.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9797
Embedded Capacitance
Input impedance of a populated 2” x 3” board with a plane separation of about 5 microns:
![Page 98: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/98.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9898
Decoupling Myth
In order to be effective, capacitors must be located within aradius of the active device equal to the distance a wave cantravel in the transition time of the circuitry.
On boards with closely spaced planes (where this rule isnormally applied) none of the capacitors on the board cantypically respond within the transition time of the circuitry nomatter where they are located.
![Page 99: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/99.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 9999
Decoupling Myth
Smaller valued capacitors (i.e. 10 pF) respond faster than highervalued capacitors.
The ability of a capacitor to supply current quickly isdetermined by its mounted inductance. The value of thecapacitance only affects its ability to respond over longerperiods of time. For a given value of inductance, higher valuedcapacitors are more effective for decoupling.
![Page 100: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/100.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 100100
Printed Circuit Board Layout Guidelines
Design rules won’t make you a good circuit board designer:
►Use common sense!
►Visualize signal current paths
►Locate antennas and crosstalk paths
►Be aware of potential EMI sources
![Page 101: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/101.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 101101
Example: How would you modify this design?
Example Design
![Page 102: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/102.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 102102
Example: A much better design
Example Design
![Page 103: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/103.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 103103
Example: How would you modify this design?
Example Design
![Page 104: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/104.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 104
Design Review
104
►Keep signal loop areas small
►Don’t locate circuitry between connectors
►Control transition times in digital signals
►Never cut gaps in a solid return plane
![Page 105: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/105.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 105105
Other design rules you may have heard of, but shouldn’t be too concerned with
►Avoid right angle corners on traces.
►20-H rule
►Multiple decoupling cap values or traces on caps
►Maximum trace lengths on striplines or microstrip traces
![Page 106: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/106.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 106
Design Example
106
![Page 107: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/107.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 107
Design Example
107
![Page 108: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/108.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 108108
Design Example 2
![Page 109: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/109.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 109109
Design Examples
![Page 110: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/110.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 110110
Summary
Don’t rely on design guidelines!►Use common sense
►Visualize signal current paths
►Locate antennas and crosstalk paths
►Be aware of potential EMI sources
►Ask other engineers to review your designs
![Page 111: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/111.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 111111
Digital GND
How do I protect components from transients on the harness?
Chassis GND
OR
Design Exercise: Where should the transient protection be grounded?
![Page 112: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/112.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 112
Diodes
0.5 volts to ~10 volts
Lowest Energy
High Capacitance (10’s of pF)
Usually fail short
Voltage limiting device
112
![Page 113: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/113.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 113
Varistors
0.5 volts to 10’s of volts
Low Energy
Higher Capacitance (10’s of pF)
Usually fail short
Voltage limiting device
113
![Page 114: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/114.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 114
Thyristors
0.5 volts to 10’s of volts
Medium Energy
Higher Capacitance (10’s of pF)
Fail open or short
Crowbar device
114
![Page 115: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/115.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 115
Gas Discharge Tubes
10’s of volts to 1000’s of volts
High Energy
Low Capacitance (< 1 pF)
Fail open
Crowbar device
115
![Page 116: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/116.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 116
Session Review
1. When is a wiring harness a transmission line, and when is it just a bundle of wires?
2. If it’s just a bundle of wires, why do I care how it’s configured or routed?
3. When do wiring harnesses look like antennas?
4. How do I design automotive components to prevent harnesses from radiating?
5. How do I protect automotive components from noise or transients on the wiring harness?
116
![Page 117: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/117.jpg)
TMFreescale, the Freescale logo, AltiVec, C-5, CodeTEST, CodeWarrior, ColdFire, C-Ware, mobileGT, PowerQUICC, StarCore, and Symphony are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. BeeKit, BeeStack, CoreNet, the Energy Efficient Solutions logo, Flexis, MXC, Platform in a Package, Processor Expert, QorIQ, QUICC Engine, SMARTMOS, TurboLink and VortiQa are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © 2010 Freescale Semiconductor, Inc. 117
For Further InformationCited Referenfces regarding Power Bus Decoupling Strategy:
T. H. Hubing, J. L. Drewniak, T. P. Van Doren, and D. Hockanson, “Power Bus Decoupling on Multilayer Printed Circuit Boards,”IEEE Transactions on Electromagnetic Compatibility, vol. EMC-37, no. 2, May 1995, pp. 155-166.
T. Zeeff and T. Hubing, “Reducing power bus impedance at resonance with lossy components,” IEEE Transactions onAdvanced Packaging, vol. 25, no. 2, May 2002, pp. 307-310.
M. Xu, T. Hubing, J. Chen, T. Van Doren, J. Drewniak and R. DuBroff, “Power bus decoupling with embedded capacitance inprinted circuit board design,” IEEE Transactions on Electromagnetic Compatibility, vol. 45, no. 1, Feb. 2003, pp. 22-30.
J. Chen, M. Xu, T. Hubing, J. Drewniak, T. Van Doren, and R. DuBroff, “Experimental evaluation of power bus decoupling on a 4-layer printed circuit board,” Proc. of the 2000 IEEE International Symposium on Electromagnetic Compatibility, WashingtonD.C., August 2000, pp. 335-338.
T. H. Hubing, T. P. Van Doren, F. Sha, J. L. Drewniak, and M. Wilhelm, “An Experimental Investigation of 4-Layer Printed CircuitBoard Decoupling,” Proceedings of the 1995 IEEE International Symposium on Electromagnetic Compatibility, Atlanta, GA,August 1995, pp. 308-312.
J. Fan, J. Drewniak, J. Knighten, N. Smith, A. Orlandi, T. Van Doren, T. Hubing and R. DuBroff, “Quantifying SMT DecouplingCapacitor Placement in DC Power-Bus Design for Multilayer PCBs,” IEEE Transactions on Electromagnetic Compatibility, vol.EMC-43, no. 4, Nov. 2001, pp. 588-599.
T. Hubing, “Printed Circuit Board Power Bus Decoupling,” LG Journal of Production Engineering, vol. 3, no. 12, December2000, pp. 17-20. (Korean language publication) .
T. Zeeff, T. Hubing, T. Van Doren and D. Pommerenke, “Analysis of simple two-capacitor low-pass filters,” IEEE Transactionson Electromagnetic Compatibility, vol. 45, no. 4, Nov. 2003, pp. 595-601.
EMC Guideline Collection: http://www.cvel.clemson.edu/emc/tutorials/guidelines.html
117
![Page 118: Solutions for EMC Issues in Automotive System Transmission ... · • Anticipate possible Electro Magnetic Compatibility (EMC) problems with your product designs • Make design decisions](https://reader030.fdocuments.in/reader030/viewer/2022040913/5e894be5686ab57d1b28ac27/html5/thumbnails/118.jpg)
TM